Some portable electronic devices comprise transducers such as loudspeakers and/or earpieces which are required to be small in size. Transducers are important components in electronic devices such as mobile phones for the purposes of playing back music or having a telephone conversation. The quality and loudness of a transducer in an electronic device are important especially where a user listens to sounds generated by an electronic device at a distance from the electronic device.
Conventional speaker or acoustic transducer apparatus is configured to generate an acoustic wave broadly in the direction of movement of the transducer and are typically wider than they are deep. A common use for such transducers is as a loudspeaker or earpiece in a mobile device. However to maintain reasonable audio quality and pass operator and type approval requirements the transducer operating as an earpiece or loudspeaker has a defined minimum volume.